Non paddle wheel speed transducers?

[jbinbi]

Not sure if this is the right thread, mods move if not....

So my paddle wheel sensor works for about the 1st 2 weeks of the season, then fouls.

I know there are some non mechanical speed sensors. Is anyone using these, and if so, can you let me know pros and cons on which model you have? Also, do they fit standard thru hole?

thanks.

[sailjumanji]

I also have interest in a speed/depth sensor without the paddle wheel. I was at the boat show">Annapolis boat show last week, and asked the B&G rep about the Airmar UDST800 ultrasonic transducer. He said doesn't work well when it gets slime on it. That said enough for me. :-(

[landonshaw]

I use iNavX, chart plotter, ais system. All have speed that is close enough for me when I am sailing

[roverhi]

Why don't you pull the transducer after a day sailing?? Raymarine, for one, have a thru hull with a rubber flap that almost seals the puka when you make the change from transducer to plug. Maybe too late for you but locating the thru hull in the bilge where a little leakage doesn't matter is a good idea.

Any speed from a GPS or plotter will have a bit of lag which isn't what you want when trying to get max speed with sail trim. it isn't giving the speed through the water except in flat, no current conditions so also not accurate for measuring sailing efficiency. Nice to have both speed through the water and over the bottom to evaluate current, wind and leeway effects.

[billknny]

We have been using an Airmar CS4500 for over two years on our cruising boat. After nearly 20K miles, I would NEVER go back to a paddle wheel. Ever.

It works every day. Once every 6 months I pull it, clean it, and apply a layer of transducer antifouling paint. It is consistently accurate and despite what some people on here have said, a light layer of slime has no effect.

It outputs standard "pulse" output like a paddle wheel, so is compatible with any standard display instrument.

You will read people posting trash about it. They haven't used it. I have.

[sailjumanji]

Originally Posted by billknny

We have been using an Airmar CS4500 for over two years on our cruising boat. After nearly 20K miles, I would NEVER go back to a paddle wheel. Ever.

It works every day. Once every 6 months I pull it, clean it, and apply a layer of transducer antifouling paint. It is consistently accurate and despite what some people on here have said, a light layer of slime has no effect.

It outputs standard "pulse" output like a paddle wheel, so is compatible with any standard display instrument.

You will read people posting trash about it. They haven't used it. I have.

It's a speed only transducer correct? I'm looking for something to replace a dual depth speed transducer.

[billknny]

CS4500 is speed only. It uses the same technology as their ultrasonic combination transducers, so I'd expect them to perform similarly.

[Tillsbury]

Originally Posted by billknny

We have been using an Airmar CS4500 for over two years on our cruising boat. After nearly 20K miles, I would NEVER go back to a paddle wheel. Ever.

It works every day. Once every 6 months I pull it, clean it, and apply a layer of transducer antifouling paint. It is consistently accurate and despite what some people on here have said, a light layer of slime has no effect.

It outputs standard "pulse" output like a paddle wheel, so is compatible with any standard display instrument.

You will read people posting trash about it. They haven't used it. I have.

Thanks for your clear recommendation. When you say "standard pulse output" does that mean that I'd be able to simply plug it into the hole where my Raymarine speed log is currently, and the other end into the ST60 instruments? No need to make new holes or pull the boat out? Or is the Raymarine not one of the "standard" ones?

[landonshaw]

There may be a lag, although while sailing for 8, 12, 24 hours it is not a concern of mine. If racing instant gratification is necessary. A standard depth gauge with the sped separate is all I have used.

[Geoff54]

Originally Posted by Tillsbury

Thanks for your clear recommendation. When you say "standard pulse output" does that mean that I'd be able to simply plug it into the hole where my Raymarine speed log is currently, and the other end into the ST60 instruments? No need to make new holes or pull the boat out? Or is the Raymarine not one of the "standard" ones?

I have ST60 instruments and briefly considered an ultrasonic sounder before I decided I had better things to spend the money on. While I was looking into it I saved this from the Raymarine forum. I have no proof that it is true but as it came from a Raymarine contributor/moderator, I assume it is...

"Raymarine offered a variant of the CS4500 for several years, but stopped doing so primarily - I believe - because of lack of demand, due to the cost.

The CS4500 is a great speed sensor and as long as you get a compatible version, will work very well with ST60, ST60+, ST70 Speed pods, i50, the ITC-5 or DSM400 sounder module. What's key is to use a '3-wire speed' variant rather than 2-wire.

The CS4500 Raymarine offered was Airmar part 44-063-1-83 (Raymarine part E26024). You can see variants of the CS4500 and compare their wiring diagrams on Airmar's transducer cross-reference in order to make sure you get the correct type."


Hope that helps but those things are expensive so do double check.

[Snore]

Originally Posted by billknny

We have been using an Airmar CS4500 for over two years on our cruising boat. After nearly 20K miles, I would NEVER go back to a paddle wheel. Ever.

It works every day. Once every 6 months I pull it, clean it, and apply a layer of transducer antifouling paint. It is consistently accurate and despite what some people on here have said, a light layer of slime has no effect.

It outputs standard "pulse" output like a paddle wheel, so is compatible with any standard display instrument.

You will read people posting trash about it. They haven't used it. I have.

Glad you like it. Can you share where you sail (salt/fresh)?

Also is it mounted vertically or horizontally off the keel?

Thanks

[seandepagnier]

Why does depth transducer work fine with slime but not speed? Any explanations offered? How far apart are the transducers?

I am developing a free software sonar. It works pinging already, and you can build it for lowest possible cost, it's fun. Also just use any old transducer, even ultrasonic cleaning transducer available for little price is what I use.

Now I plan to make it also measure water speed, but placing two or more transducers around the boat. To measure water speed in this way, a _much_ more accurate timing is needed than simple depth, but it can measure water temperature at the same time which improves depth accuracy as well. Also in question is if in-hull transducers can work for this. That would be nice.

[wiekeith]

Originally Posted by boat_alexandra

Why does depth transducer work fine with slime but not speed? Any explanations offered?

I seem to recall reading that because it's measuring reflections from very small particles in, and moving with, the water, it uses a different technique (frequency range?) to standard depth transducers. But I may be mistaken.

[Oceanride007]

Would like to know if ultasonic measurement of speed, is affected by which Tack you are on. They say they measure at depth but my keel has long leading edge.

ie. My paddle wheel is mounted about a ft outboard of the leading edge of keel on Port side. When on Port tack a lot more water races around the leading edge to the Port side, giving me a false much higher reading.
Won't the Airmar Cs4500 but to a lesser extent be effected similarly. At least with the Paddle wheel I can point it to wards Port more, compensating it and recalibration. Not great solution.

[stnick]

I had a Airmar wheelless transducer for speed on my sabre 28 after a month it stopped The neighbor in our marina got a lightning strike. Fried my speed transducer. Removed it with Marine formula a spray that eats 5200 . We sent it back to airmar and they would not stand behind there product . I purchased another ! It lasted 4 months ! I removed it and put a plug back in the hole. Im done with that product.